The broad potential for using nucleic acids to treat human disease has not been realized. Delivery of nucleic acids for the purpose of regulating gene expression in cultured cells has been routine in many laboratories for twenty years. Over 350 rare monogenic disorders cause disease in the skin, and common inflammatory diseases affecting several percent of the population, such as psoriasis, have well-understood molecular pathways that could be the targets of nucleic acid therapeutics. It is not hard to imagine well over 350 distinct nucleic acid drugs designed to treat specific skin diseases. Yet, apart from use in vaccines, no nucleic acids are approved for use in human skin. Delivery appears to be the major obstacle to progress in developing nucleic acid therapeutics for skin. Intradermal injections appear to deliver nucleic acids to epidermal cells, but the large cutaneous surface makes such an approach impractical. A wide range of innovative physical and chemical methods are being investigated with the aim of enhancing delivery to skin, but the lack of consistent and relevant skin models and analysis tools has impeded comparative studies and optimization of protocols. No one investigator is likely to have the skill, knowledge and equipment needed to readily compare delivery options for his/her own favorite nucleic acid/delivery method, which s/he has shown to be biologically active in cell culture, and in some cases, tissue models. Without such validated systems, progress in evaluating newly designed specific nucleic acid sequences and chemical modifications designed to improve their effectiveness will be extremely difficult. The goal of this proposal is to bridge the gap between test tube knowledge and clinical application. We will develop reagents, model assay systems and analysis tools that can be used in a validated and transferable algorithm for testing delivery of nucleic acids to cells in the epidermis. Because our models are activated by successful delivery, changes at the single cell level will be detectable. There will be three parallel tracks: the first track will test delivery of reporter plasmid DNA;the second track will test delivery of biologically active nucleic acids that target mRNA;the third track will test delivery of biologically active nucleic acids that target chromosomal DNA. We will develop a molecular reporter, which with small modifications, can be used to test biologically relevant, sequence-specific activity of any small nucleic acid. We will develop models of mouse skin and human skin equivalents grafted onto mice as standard assays. We will use new sensitive and quantitative imaging devices to compare delivery methods that include, but need not be limited to: electroporation, sonoporation, iontophoresis, liquid jets, microneedles and topical formulations. The work and discoveries made by the major U.S. participants in this application, TransDerm, Yale, Stanford, Lucid, Stratatech, as well as the investigators from collaborating institutions (UCSB, Alnylam Pharmaceuticals (Cambridge, MA), Univ. S. Florida, Old Dominion Univ., Traversa Therapeutics (San Diego), NT Omics (Seattle), etc) have the potential to benefit many tens of thousands of patients with skin disease, and will certainly impact the local economies. In recent years, Stanford and Yale Universities pumped more than $3 billion into their local economies. Discoveries by investigators at Stanford and Yale have led to the creation of dozens of companies, which continue to provide jobs and stimulate the economy. The current proposal would positively impact the economy by creating or retaining 4 jobs at TransDerm, 2.35 jobs at Yale, and 3 jobs at Stanford. According to the California Biomedical Industry, for every one employee of a biomedical organization, another three to five will be employed in firms that service that industry. This proposal could have definite employment implications for two of our small company collaborators, Stratatech and Lucid. If the goal of this work succeeds, it is expected that the pace of new research and development of nucleic treatments for skin disease will accelerate greatly, spawning many new jobs and small companies.